The northernmost
destination of the cruise is Hubbard Glacier. According
to a
report by the U.S. Geological Survey, it is the
largest tidewater glacier on the North American continent.
It is also significant because it is advancing, rather
than shrinking. The ship slowly passes by the glacier,
and if you're lucky, you can see it calving, when a
big chunk of ice falls, and sends out a massive shower
of water. It sounds like thunder when the chunk falls
from the face of the glacier.